package cn.edu.dgut.css.sai.security.oauth2.util;


import org.apache.commons.lang3.StringUtils;

import javax.servlet.http.HttpServletRequest;

/**
 * 获取用户请求的Ip地址工具类
 *
 * @author sai
 * @since 1.0
 */
public class IpAddressUtil {

    /**
     * 获取用户请求的Ip地址
     *
     * @param request {@link HttpServletRequest}
     * @return String
     * 参考：https://blog.csdn.net/chwshuang/article/details/71940858
     */
    public static String getRequestIpAdrress(HttpServletRequest request) {
        String Xip = request.getHeader("X-Real-IP");
        String XFor = request.getHeader("X-Forwarded-For");
        if (StringUtils.isNotEmpty(XFor) && !"unKnown".equalsIgnoreCase(XFor)) {
            //多次反向代理后会有多个ip值，第一个ip才是真实ip
            int index = XFor.indexOf(",");
            if (index != -1) {
                return XFor.substring(0, index);
            } else {
                return XFor;
            }
        }
        XFor = Xip;
        if (StringUtils.isNotEmpty(XFor) && !"unKnown".equalsIgnoreCase(XFor)) {
            return XFor;
        }
        if (StringUtils.isBlank(XFor) || "unknown".equalsIgnoreCase(XFor)) {
            XFor = request.getHeader("Proxy-Client-IP");
        }
        if (StringUtils.isBlank(XFor) || "unknown".equalsIgnoreCase(XFor)) {
            XFor = request.getHeader("WL-Proxy-Client-IP");
        }
        if (StringUtils.isBlank(XFor) || "unknown".equalsIgnoreCase(XFor)) {
            XFor = request.getHeader("HTTP_CLIENT_IP");
        }
        if (StringUtils.isBlank(XFor) || "unknown".equalsIgnoreCase(XFor)) {
            XFor = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (StringUtils.isBlank(XFor) || "unknown".equalsIgnoreCase(XFor)) {
            XFor = request.getRemoteAddr();
        }
        return XFor;
    }
}
